Typerod

So today I was working on my 07 Tahoe LTZ, I replaced the front impact airbag sensor. I disconnected my neg. battery cables. I have dual batteries. Then I notice there seems be to a crack in the battery case leading to the neg. battery terminal. And I can see acid or electrolyte(?) that has seeped out and dried up. I also notice that there is some subtle bulging on top of the battery but not sure if that has been there ever since I installed it 6 years ago (which I doubt, lol) or if this battery is on a slow pace to expand out of its case.

I installed these dual batts back in December of 2010, and have had no issue at all. I know popular opinion will be to replace it! lol! But that means I have to replace the other battery as well. Both batts are Optima yellow tops, D35 is the model number.

So what do you guys think?

Scotiapilot

I have dual bats also and I learned my lesson but good, when one goes bad you must replace both at the same time. Mt hellish nightmare never ended until I replaced both. Would I replace the one you posted? If it is leaking OR vented yes it will die

justimagination

Save yourself from unexpected breakdown, replace the batteries. Good luck
David g.

Typerod

I knew it! LOL! jk! I plan on buying a set of Odyssey 48-720's. I google searched the cracked cased in my optima and see that a few other people have had this same issue. But I may check Costco first, to see if they have and AGM batts. Last I saw Costco had Interstate batts but were not AGM.

Thanks all!

73shark

Do the Optimas require three stage charging like other AGMs? If they do, how does the vehicle charging system handle this?

intheburbs

If you have a system with a battery isolator, it's not necessary for the two batteries to be identical or replaced at the same time. The only time they're connected is when the engine is on and charging them.

I'm not sure what you mean by this. I've had dual AGMs in my Suburban for three years with no issues. This truck has seen temperatures from -20° to 115°. The charging system seems to handle them just fine.

Typerod

Hi Shark, I'm not familiar with the 3 stage charging you mention. I've had this setup just about 6 years with no issues with charging thru the alternator or charging by external batt. charger.

I do not have an isolator, I wish I did install one, but I didn't feel confident enough to follow the diagram that I saw before hand using Painless Performance's isolator. lol!

73shark

I know that Lifeline battery recommends for their AGM batteries using a three stage charger. The three stages are bulk, absorption, and float and should have temperature compensation. Since I used Lifelines for my RV house batteries, never checked Optima's recommendation.

intheburbs

Yes, I'm aware of three-stage charging. But how does this translate to your alternator/charging system? I've never seen anything where an automotive charging system is incompatible with AGM batteries.

Or are you talking about the rare circumstances where you want to charge the batteries using a plugin charger?

73shark

No idea how an automotive charging system affects an AGM battery. I doubt that it extends the life of the battery tho.